The present invention relates to sunscreens. In particular, the present invention relates to sunscreens which can be applied to a person whose skin is wet or dry and which achieves its fill SPF instantly, irrespective of whether it was applied to wet or dry skin. The invention further relates to inventive procedures for testing the effectiveness of sunscreens.
In recent years, the dangers of exposing the skin to direct sunlight have become known. Consequently, the concept of having a "healthy" tan has changed to one of protecting the skin from the harmful effects caused by exposure, particularly to the ultraviolet ("UV") rays of the sun, which have been shown to cause many skin problems, including cancers, such as melanoma. These effects have been shown to be cumulative over a person's life, and no way has been found to reverse these effects.
Accordingly, modern thinking involves not exposing one's skin to the direct rays of the sun unless the skin is either covered or otherwise protected. Numerous sun screen products are available to protect the skin from the harmfull rays of the sun. These sunscreen products are rated based upon their ability to protect the user's skin, using a rating system which is based upon a Sun Protection Factor ("SPF") rating. The higher the SPF of a sunscreen, the greater the amount of protection which the sunscreen provides to a user.
Among the various sunscreens which are available are a number which are called either "water resistant" or "waterproof". What consumers do not generally recognize, however, is that such sunscreens are only water resistant or waterproof after they have been applied to the user, and after they have been allowed to dry, whereby they are, themselves, protected from water by a thin film. In accordance with the instructions and test procedures used with such so-called "water resistant" and "waterproof" sunscreens of the prior art and generally not known by, or, alternatively, disregarded by, consumers, is that the sunscreens must be applied to the dry skin of a user in order for them to have the SPF which they claim to have. In fact, the very test procedures heretofore used to test the efficacy of sunscreens requires that the sunscreens be applied only to dry skin.
The so-called "water resistant" and "waterproof" sunscreens of the prior art, must all be applied to dry skin, then allowed to dry on the user's skin for a period of time, typically twenty minutes, before they are effective. In fact, while no rules have been adopted by the federal Food and Drug Administration ("FDA"), the industry has operated pursuant to the proposed rules which were published on May 12, 1993 in Volume 58, No. 90 of the Federal Register, which require a waiting period of at least 15 minutes before exposure prior to testing the SPF of a sunscreen. Similarly, the proposed rules also set forth a methodology for determining the water resistance of a sunscreen product. In accordance with the water resistance testing, a determination is made as to whether a sunscreen is able to retain the same Product Category Designation ("PCD"). As is known by those skilled in the art, the PCD of a sunscreen is based upon its SPF value, as follows: "minimal" means the sunscreen has an SPF from 2 to less than 4; "moderate" means the sunscreen has an SPF from 4 to less than 8; "high" means the sunscreen has an SPF from 8 to less than 12; "very high" means the sunscreen has an SPF from 12 to less than 20; and "ultrahigh" means the sunscreen has an SPF of from 20 to 30.
In reality, many people who are out in the sun have wet skin prior to their applying any sunscreen agent. Such people are often engaged in activities associated with a proximity to water, such as swimming, boating, or fishing which are conducive to their skin becoming wet. Attentively, people who are out in the hot sun, or are engaged in strenuous outdoor activities, such as sports, are prone to sweating, which also causes their skin to become wet.
The application of a sunscreen to wet skin, even those sunscreens which are "water resistant" or "waterproof" is contrary to their instructions for use and prevents them from having the efficacy which they proclaim to have when applied properly to dry skin and allowed to dry for the requisite time prior to the person being exposed to the sun.
In view of the foregoing, a new class of sunscreens, i.e., sunscreens which can be applied directly to wet skin, is needed. In addition, cosmetics, such as makeup, can be formulated to include the instant protection and "wet-appliable" benefits of the present invention. Finally, procedures for testing such "wet-appliable" sunscreens for efficacy are also needed.
As used herein, various trademarks and trade names are intended to refer to their chemical names as set forth in the following table:
Trade Name Material CAS # GANEX V220 PVP/EICOSENE COPOLYMER 28211-18-9 POLYETHYLENE POLYETHYLENE 9002-88-4 PVP/VA W735 PVP/VA COPOLYMER 25086-89-9 PLANTAREN 2000 DECYL GLUCOSIDE 58846-77-8 GERMABEN II PROPYLENE GLYCOL (AND) 57-55-6 DIAZOLIDINYL UREA (AND) 78491-02-8 METHYLPARABEN (AND) 99-76-3 PROPYLPARABEN 94-13-3 DC 345 CYCLOMETHICONE 69430-24-6 N-HANCE AG50 C1-5 ALKYL GALACTOMANNAN N-HANCE AG200 C1-5 ALKYL GALACTOMANNAN SF 1328 (NEW SF 1528) CYCLOPENTASILOXANE (AND) 69430-24-6 DIMETHECONE COPOLYOL 64365-23-7 DC 345 CYCLOMETHICONE 69430-24-6 ESCALOL 557 OCTYL METHOXYCINNAMATE 5466-77-3 TRIVENT DIDA DIISODECYL ADIPATE 27178-16-1 ARLACEL P135 PEG-30 DIPOLYHYDROXY-STEARATE 70142-34-6 GANEX V220 PVP/EICOSENE COPOLYMER 28211-18-9 CASTORWAX MP7O HYDROGENATED CASTOR OIL 8001-78-3 Z-COTE ZINC OXIDE GERMABEN II-E PROPYLENE GLYCOL (AND) 57-55-6 DIAZOLII)LNYL UREA (AND) 78491-02-8 METHYLPARABEN (AND) 99-76-3 PROPYLPARABEN 94-13-3